我已经创建了一个 android 应用程序,用户可以在其中选择位置的起点和终点。此应用程序将使用 Google-Direction 网络服务并发出 HTTPRequest。我会简短地说,我想从 main_activity 调用 JSONParser 类中的 asynctask 方法。问题是,我不知道如何在 main_activtiy 方法中显示结果
这是异步任务方法
public class JSONParser {
InputStream is = null;
JSONObject jObj = null;
String json = "";
public JSONParser() {
}
public void getJSONFromUrl(final String url, final responseListener target) {
new AsyncTask<Void, Void, String>() {
protected String doInBackground(Void... params) {
HttpURLConnection httpURLConnection = null;
StringBuilder stringBuilder = new StringBuilder();
try {
httpURLConnection = (HttpURLConnection) new URL(url).openConnection();
InputStreamReader inputStreamReader = new InputStreamReader(httpURLConnection.getInputStream());
int read;
char[] buff = new char[1024];
while ((read = inputStreamReader.read(buff)) != -1) {
stringBuilder.append(buff, 0, read);
}
return stringBuilder.toString();
} catch (MalformedURLException localMalformedURLException) {
return "";
} catch (IOException localIOException) {
return "";
} finally {
if (httpURLConnection != null)
httpURLConnection.disconnect();
}
}
protected void onPostExecute(String result) {
super.onPostExecute(result);
target.onResponseComplete(result);
}
}.execute();
}
这是主要方法调用方法的方式
new JSONParser().getJSONFromUrl(url, new responseListener() {
@Override
public void onResponseComplete(String response) {
try {
ArrayList<HashMap<String, Object>> list = new ArrayList<HashMap<String, Object>>();
JSONArray step = new JSONObject(response).getJSONArray("routes").getJSONObject(0).getJSONArray("legs")
.getJSONObject(0).getJSONArray("steps");
for (int i = 0; i < step.length(); i++) {
HashMap<String,Object> row = new HashMap<String,Object>();
row.put("Distance", step.getJSONObject(i).getJSONObject("distance").getString("text"));
list.add(row);
}
}catch (Exception e){
e.printStackTrace();
}
}
});
}
正确的问题是我想如何显示 Arraylist List 值并将其放入 TextView 调用 jarak